The rotation speed and the crank position of an engine in an engine stopping process are detected; then, in the case where when the detected crank position is at an intermediate point between the top dead center of any one of the cylinders and the top dead center of the cylinder following said one of the cylinders, it is determined that the engine rotation speed is within a predetermined range, drive of the starter is prohibited for a predetermined time period.

An electric motor for starting internal combustion engines and a relative starting control system of such engine comprising said electric motor of the type with permanent magnets allows a more effective and simpler management of the internal combustion engine thereto the electric motor is connected, wherein a monitoring unit of the electric motor (EMU) and a monitoring unit of the internal combustion engine (ECU) are provided, wherein the electric motor comprises a direction sensor (18) providing a signal representing the rotation direction of the rotor (12) of the electric motor, which is connected to said monitoring unit of the internal combustion engine (ECU).

A method of controlling a powertrain of a vehicle includes opening and/or closing one or more of a first switching device, a second switching device, a third switching device, and engaging and/or disengaging at least one of a pair of actuators for a starter mechanism or a motor/generator clutch. Many different control modes are provided for the powertrain by changing the operation of a motor-generator between a motor or a generator, and changing the electrical connections between a first energy storage device, a second energy storage device, an auxiliary electric system, the starter mechanism, and the motor-generator.

There is provided a vehicle-mounted control device that, when a restart request is generated during a time interval between the fulfillment of an engine automatic stop condition and complete stop, decreases a charging efficiency of an engine by means of at least one of a throttle valve and an intake valve to prevent an increase in the reverse rotational frequency of the engine, thereby ensuring the durability of the starting device of the engine, and preventing an accelerator response from deteriorating when a restart request based on the accelerator operation is generated. In the vehicle-mounted control device that controls a charging efficiency of the engine on the basis of the requested engine output amount, the engine is automatically stopped when a predetermined automatic stop condition is fulfilled, and a charging efficiency at the time when a restart condition of the engine has been fulfilled on the basis of an engine output request generated during a time interval between the fulfillment of the automatic stop condition and complete stop of the engine is made lower than a charging efficiency for the requested engine output amount.

A starting control device for an engine includes an ECU configured to: i) execute an autonomous starting control in which the ECU injects fuel into the cylinder from a fuel injection valve after a crank shaft rotates reversely before the crank shaft stops its rotation and then ignites an air-fuel mixture using an ignition plug to start the engine without using a starter motor; ii) determine whether a pressure in the cylinder increasing due to the reverse rotation is equal to or greater than a predetermined pressure at a time point of firing of the air-fuel mixture by the ignition; and iii) prohibit starting of the engine under the autonomous starting control when the ECU determines that the pressure in the cylinder is not equal to or greater than the predetermined pressure.

A vehicle has a frame, a front suspension assembly, a pair of skis, an endless drive track, and an internal combustion engine. The engine has: a motor-generator having a rotor and a stator, the motor-generator being operable in motor mode and in generator mode; a recoil starter operable to rotate a crankshaft of the engine via the rotor in a same direction as does the motor-generator in generator mode; at least one sensor adapted for sensing at least one engine parameter; and an engine control unit (ECU) receiving a signal from the at least one sensor, the ECU controlling a rotation of the crankshaft by one of the motor-generator and the recoil starter based on the signal.

A control device for an engine of the invention executes an automatic stop control for stopping stop a rotation of a crank shaft when a predetermined automatic stop condition is satisfied. The device acquires a focused peak value of the engine speed appearing after a time when a rotation direction of the crank shaft first reverses while the automatic stop control has been executed, determines, based on the focused peak value, whether there will be an excessive peak value expected to depart from a predetermined permission range after the focused peak value appears, and executes a starter start control for driving the starter, restarting the fuel supply and igniting the fuel to restart an operation of the engine when a predetermined restart condition is satisfied, the engine speed is within the predetermined permission range and it has been determined that there will be no excessive peak value.

A process for starting an internal combustion engine, providing the use of an electric motor acting on the driveshaft of the internal combustion engine, provides a positioning step, activated upon switching-off the engine, and a switching-on step, activated after a starting control, wherein said positioning step comprises: a forward rotation by a predetermined forward rotation angle; a detection of a possible stall state followed, in negative case, by an additional forward rotation until reaching a predetermined maximum forward rotation angle; an inverse rotation by a predetermined angle; and a detection of a possible stall state followed, in negative case, by an additional inverse rotation until reaching a predetermined maximum inverse rotation angle.

The rotation speed and the crank position of an engine in an engine stopping process are detected; then, in the case where when the detected crank position is at an intermediate point between the top death center of any one of the cylinders and the top death center of the cylinder following said one of the cylinders, it is determined that the engine rotation speed is within a predetermined range, drive of the starter is prohibited for a predetermined time period.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.